Telephone system.



Patented Apr. 24,1917.

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H. P. CLAUSEN.

TELEPHONE SYSTEM.

APPLICATION man Auenz. 1915.

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HENRY P. CLAUSEN, OF MOUNT VERNON, NEW YORK, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO WESTERN ELECTRIC COMPANY, INCORPORATED, A CORPORATION OF NEW YORK.

TELEPHONE SYSTEM.

Specication of Letters Patent.

Patented Apr. 241, 1917.

To all whom t may concern:

Be it known that I, HENRY P. CLAUSEN, a citizen of the United States, residing at Mount Vernon, in the county of Vestches- `ter and State of New York, have invented certain new and useful Improvements in Telephone Systems, of which the following is a full, clear, concise, and eXact description.

This invention relates to telephone systems of the manual type and more particularly to such systems in which trunk connecting circuits are employed.

The object of this invention is to provide means for assisting an answering operator and a switching operator in the supervision and control of their respective connecting circuits.

In accordance with the general features of this invention, means are provided for giving both an answering operator and a switching operator a warning signal in case the switching Operator prematurely withdraws the calling end of her connecting circuit from the line jack of va called subscribers line. When this occurs the switching operator is given both a visual and an audible signal indicating her mistake, while the answering operator receives a characteristic signal which may comprise the flashing of her supervisory lamp included in the calling end of her connecting circuit.

Means are also provided forI notifying the switching Operator in the event the answering operator inadvertently disconnects her connecting circuit forming a part of a connection unitingtwo subscribers lines for conversational purposes.

In the drawing there is shown a subscribers substation C connected by means of line wires 1, 2 to a line jack 3 located at a B exchange. Included in the line circuit is the usual line relay 4f, which controls the line lamp 5 and a cutoff relay 6. Only ,the equipment necessary to illustrate this invention is shown for the answering operators cord circuit located at an A eX- change. The equipment shown comprises a calling plug 7 having included in the talking strands thereof the usual supervisory relays 8 and 9 which conjointly control a supervisory lamp l10. In the switching or B operator-s cord circuit, besides the customary equipment, there is furnished an interrupting device and a tone producing device with the necessary apparatus to control the circuits of these devices under the conditions contemplated by this invention.

In describing the operation of the apparatus shown in the drawing, we may assume that an A operator inserted the calling plug 7 into the jack 11 of the outgoing end of a trunk line running to the B oiiice. This would effect the closure of the following circuit: battery, coil of relay 8, ring strand of the plug 7 land jack 11 respectively, portion 13 of the 'trunk repeating coil, conductors 14, 15, coil of relay 12, conductor 16, contact 17, conductor 37 portion 1S of the repeating coil, tip side of the jack 11 and plug 7 respectively, coil of relay 9, to ground. The closure of this circuit establishes an energizing circuit for the relay 12, which in pulling up its right hand armature closes contact 20, thus completing a circuit through the lamp 19 which may be traced as follows: battery, lamp 19, contact 20, conductor 21, contact 22, to ground. 'The B operator observing the lamp 19 lighted will know thatconnection has been made with the outgoing end of this particular trunk by an A operator. Having learned from the A operator that connection is desired with subscriber C, by means of an order wire (not shown) connecting the eX- changes, the B operator will insert the calling plug 25 into the line jack 3. This closes a circuit through the relay 26 of the B operators connecting circuit which may be traced as follows: battery, coil of relay 26, ring strand of the plug 25 and jack 3 respectively, coil of relay 6, to ground. The energization of the relay 26 extinguishes the lamp 19 by the opening of contact 22.

One of the circuits, completed upon the actuation of the relay 26, is through a guard and ringing lamp 27, which circuit may be described as follows: battery, lamp 27, contact 28, conductors 29, 30, 31, contact 32 to ground. A second circuit, completed at this time, includes the relay 33 and may be traced as follows: battery, coil of relay 33, conductor 31, contact 32, to ground.

Ringing currentmay be applied to subscriber Cs line by actuating the ringing key 23. station C, a circuit is established through the tip supervisory relay 24, which may be described as follows: battery, coil of relay 26, ring side of the plug 25 and jack 3 respec- Upon the removal of the receiver at sub-- tively, line wire 1, through substation C, back over line wire 2, tip side of the jack 3 and plug 25 respectively, coil of relay 24, to ground. By the energization of the supervisory relay 24 several circuits are completed, one of which causes the substitution of the relay 34 for the relay 12 in the energizing circuit of the supervisory relays 8 and 9 of the A operators cord circuit. This substitution is accomplished by the closure of front contact of relay 24 which completes the fol lowing circuit: battery, coil of relay 8, ring strand of the plug 7 and jack 11 respectively, portion 13 of the trunk repeating coil, conductor 14, coil of relay 34, con ductor 36, contact 35, conductor 37, portion 18 of the repeating coil, tip spring of the jack 11 and plug 7 respectively, coil of relay 9, to ground. It may be mentioned here that the relay 12 is of high resistance and the relay 34 is of low resistance, and the interchanging of these two relays, in the manner described above, permits the energization of the relay 9 which heretofore has not received sufficient current to cause it to be operated. rlfhe relay 9 in pulling up its armature interrupts the circuit for the supervisory lamp 10, which indicates to the A operator that the called subscriber has responded.

A second circuit, closed by the energizai tion of the relay 24 effects the energization A to ground.

of the relay 38 over the following path: battery, coil of relay 38, conductor 40, contact 41, conductors 42, 30, 31, contact 32, to ground. It will be observed that the relay 38 in pulling up its armature establishes an energizing circuit for itself which may be traced as follows: battery, coil of relay 38, contact 39, conductors 29, 30, 31, contact 32, to ground. The opening of the contact 28 upon the energization of the relay 38 eX- tinguishes the lamp 27, which is an indication to the B operator that the called party has answered.

Let us assume that the B operator prematurely disconnected the plug 25 from the jack 3 of the called subscribers line. In such an event the relays 24 and 26 will become denergized. The denergization of the relay 26, in permitting its left-hand armature to fall baclr, closes contact 22, establishinor the following circuit for the relay 45; battery, lamp 19, conductor 46,

' Contact 47, conductors 48, 49, coil of relay 45, contact 50, conductor 51, contacts 52, 22, It may be stated here that the relay 33 is of a type slow in releasing and remains energized long enough to permit the closure of the circuit ust described after its own energizing circuit has been interrupted by the denergization of the relay 26. It may also be stated that the contacts 50 and 53 are make-before-break contacts, and

a when the relay 45 becomes energized the contact 53 forms a part of the energizing circuit for said relay, which circuit may be traced as follows: battery, lamp 19, conductor 46, contact 47, conductors 48, 49, coil of relay 45, contact 53, conductor 54, contact 22, to ground.

A circuit, completed by the actuation of the relay 45, includes a tone producing device 55, which circuit may be traced over the following path: battery, interrupter 55, conductor 5G, contact 57, conductor 58, contact 59, conductor GO, winding of induction coil 61, to ground. The closure of this circuit gives the B operator an audible signal in her head set, indicating to her that she has prematurely withdrawn the plug 25 from the jack 3. In addition to this tone the B operator will receive a visual signal, which constitutes the flashing of the lamp 19, by the energization of the relay 12, as the latter is interchanged with the relay 34 in the energizing circuit of the supervisory relays 8 and 9 of the A o-perators connecting circuit by the alternate energization and denergiza tion of the relay 24 effected by a circuit interrupting device 62. An energizing circuit for the relay 24 is established periodically by the interrupter 62 over the following path: battery, interrupter G2, contact 63, conductor G4, tip strand of the cord circuit, coil of relay 24, to ground. The energization of the relay 24 over the circuit just traced, effects the substitution of the relay 34, for the relay 12 in the energizing circuit for the supervisory relays 8 and 9 in the manner hereinbefore set forth. When this substitution occurs, a new energizing circuit is established for the relay 45 -which may be described as follows: battery, contact 70, conductor 49, coil of relay 45, contact 53, conductor 54, contact 22, to ground. To insure the constant cnergization of the relay 45 during the interclianging of the relays 12 and 34, it is preferable to have the relay 12 of a type slow in releasing so that contact of relay will be closed before contact 47 of relay 12 will be opened. The alternate energization and denergization of the relay 12 produces the flashing of the lamp 19.

The alternate energization and de'e'nergization of the relay 24 produced by the interrupter 62 also effects the flashing of the A i operators supervisory lamp 10, by the interchanging of the relays 12 and 34 in the circuit including the supervisory relays 8 and 9, for the reason as hereinbefore stated, that, when the relay 12 is included in an energizing circuit of said supervisory relays, the relay 9 does not receive suflicient current tol cause its operation. The relays 8 and 9, in exercising control over the circuit for the supervisory lamp 10,' will open and close the circuit for said lamp when the relay 9 is energized and denergized, thus causing said lamp to be flashed. The flashing of the yso lamp 10 may comprise a notification to the A operator that the disconnection of the calling end of the trunk circuit Was premature on the part or' the B operator. As both the A and B 'operators receive Warning signals simultaneously of the mistake on the part of the B operator, in many cases it would be possible to reestablish the connection With the called subscribers line Without seriously discommoding or inconveniencing either of the connected subscribers.

N 0W let us assume that the A operator inadvertently withdrew her calling plug 7 from the jack 11 of the trunk circuit. In this case the relay 34 would become denergized, permitting the completion of the following circuit for the lamp 19: battery, lamp 19, contact 66, conductor 67, contact 65, conductors 68, 31, contact 3Q, to ground. The lighting of the lamp 19 may now serve as an indication to the B operator that the connection between the conversing subscribers was prematurely interrupted on the part of the A operator, and she may take any steps necessary to reestablish connection between the talking subscribers.

From the above it Will be seen that by the means contemplated by this invention, Where interoiiice calls or calls necessitating the use of trunk lines are prematurely disconnected, in many cases the connection may be restablished Without grievously inconveniencing the connected subscribers. Better supervision Will result on the part of both a sending and a switching operator, due to the fact that each receives a Warning signal almost instantaneously upon the accidental disconnection or interruption of such calls.

lVhat is claimed is:

1. In a telephone system, a main exchange, a sub-exchange, telephone lines terminating at each exchange, a trunk line extending from the'main exchange to the sub-exchange, a connecting circuit at the main exchange for connecting a calling line with a trunk line, a signal associated With said connecting circuit, means for actuating said signal when said connecting circuit is connected through said trunk to a called line, means for retiring said signal when the called subscriber responds, and a second means for actuating said signal when the trunk is disconnected from a called line, said second means conditioned to operate While the trunk and connecting means are united.

2. In a telephone system, a main exchange, a sub-exchange, telephone lines terminating at each exchange, a trunk line extending from the main exchange to the subexchange, a connecting circuit at the main exchange for connectinga calling line With a. trunk line, a supervisory lamp associated,

with said connecting circuit, means for lighting said lamp when said connecting circuit is connected to said trunk line, means for extinguishing said lamp when a called subscriber united by said connecting circuit and trunk line responds, and a second means for actuating said lamp when the trunk is disconnected from the called line, said second means conditioned to operate While the trunk and connecting circuits are united.

3. In a telephone system, a main exchange, a sub-exchange, telephone lines tei minating at each exchange, a trunk line extending from the main exchange to the subexchange, a connecting circuit at the main exchange for connecting a calling line With a trunk line, a tone producing device associated With said trunk circuit, said device being actuated by the disconnection of the trunk line from a called line, While the trunk and connecting circuits are united.

4f.. In a telephone system, a main exchange, a sub-exchange, telephone lines terminating at each exchange, a trunk line eX- tending from the main exchange to the subexchange, a connecting circuit at the main exchange for connecting a calling line With a trunk line, a supervisory lamp associated With said connecting circuit, circuits for controlling said lamp when said connecting circuit is united With said trunk line, said lamp being lighted When one of said circuits is closed, said lamp being retired When another of saidcircuits is closed, means for controlling said control circuits, said means being inactive when said connecting circuit is united With said trunk line permitting the closure of said lighting circuit for said lamp, said means being active when a called subscriber connected by said connecting circuit and trunk line responds thereby effecting the closure of said retiring circuit for said lamp, and a second means for controlling said control circuits conditioned to operate when the trunk is disconnected from the called line and said trunk and connecting circuits are united, said second means being adapted to effect the activity and inactivity of said control means thereby causing said lamp to be flashed.

5. In a telephone system, a main exchange, a sub-exchange, telephone lines terminating at each exchange, a trunk line extending from the main exchange to the subexchange, a connecting circuit at the main exchange for connecting a calling line with a trunk line, a supervisory lamp associated with said connecting circuit, circuits for controlling said lamp When said connecting circuit is united with said trunk line, one of said circuits comprising a high resistance path for lighting said lamp When completed, another of said circuits including a low resistance path for retiring said lamp when completed, means for controlling said circuits, said means being inactive when said connecting circuit is united With said trunk line permitting the closure of said high resistance circuit, said means being active when a called subscriber connected by said connecting circuit and trunk line responds thereby effecting the :retiringof said lamp by the closure of said 10W-resistance circuit, and a second means for controlling said control-means conditioned to ll0 operate when the trunk is disconnected from the called line and said trunk and connecting circuits are united, said second means being adapted to e`ect the activity and inactivity of said control-means thereby causing said lamp to be flashed.

In Witness whereof,- I hereunto subscribe my name this 16th day of August A. D., 1915.

HENRY P. CLAUSEN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. C. 

